The file 1-open has a hole for glueing in whatever fits, 2-open two holes. The file 1-closed has a hidden magnet, 2-closed two of them. The holes will be closed while printing. Put a printing stop in your slicer at the last layer with the hole.
I printed it scaled 100%, magnets with d=10mm and h=2mm will fit perfect.
Printed lying on the back without support. Use the two holes version if you need more power.
The author remixed this model.